The present invention relates generally to sash-type windows and, more particularly, to a locking device used to maintain the window sash in position with respect to the window frame.
One common type of window used in building structures is a horizontally operating window wherein a frame is mounted within the window opening about its periphery. A window sash, containing glass or other window material, is slidably mounted within the frame, and is horizontally movable along the frame for opening or closing of the window. Windows of this type are typically formed from aluminum extrusions or wood pieces, which are assembled to define the window frame and sash.
Often, it is desired to secure the movable sash in position with the frame. The most common case is where the window is locked into a closed position for security purposes, or simply to discourge opening of the window as where the building is air conditioned. However, it may also be desirable to lock the sash into an open position. For example, movement of the sash could be discouraged for security reasons, to assure ventilation, or to protect occupants such as children. Of course, similar concerns exist with respect to vertically operating sash-type windows.
What is needed, therefore, is a means of preventing or discouraging unwanted sliding movement of the window sash within the frame. Such a device should be reliable and easy to operate. It should also be inexpensive and simple to manufacture, as well as easy to install on or within the window assembly. The device should not require the use of specialized parts in the window assembly itself, or require significant modification to the window components. The device should be specifically adapted for horizontally operating windows, but should also be capable of use with vertically-operating windows.